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Last week we discussed how run-off can
occur two different ways:
Surface Run-off – water flowing on the
surface to streams, rivers and oceans.
 Subsurface Run-off – water absorbed by and
flowing under the ground. It still flows back
to oceans.
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Aeration Zone – the zone that lies between the
water table and the Earth’s surface
Saturation Zone – The layer of an aquifer
where the pore space is completely filled with
water.
Water Table – the boundary line of the zone of
saturation.
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Infiltration is the process of water entering the
soil.
Since water has infiltrated (entered) the soil, it
is considered groundwater.
POROSITY
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Groundwater seeps
down through the soil
and fills the pores, or
spaces between rock
particles.
Porosity is the indicator
of how much
groundwater those
pores can store.
PERMEABILITY
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Sometimes the pores in
the ground are
connected to each other.
Permeability is the ease
that water can pass
through a porous
material.
A substance is
impermeable if water
cannot flow through it.
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Which picture shows greater porosity?
Which picture shows lesser porosity?
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Which picture shows the most permeability?
Which picture shows the least permeability?
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An underground body of rock or sediment
where large amounts of water can flow and be
stored is called an aquifer.
Wells and Springs
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A WELL is a
manmade hole dug in
order to access
groundwater.
It is manmade, so it is
not natural.
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A SPRING is a place
where the water table
naturally meets the
ground’s surface.
It is a natural flowing
of water from a
natural hole in the
ground.
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Wells and springs are divided into two groups
– Ordinary
- Artesian
ORDINARY WELL

An ordinary well is a
hole that is dug below
the water table to bring
groundwater to the
surface
ORDINARY SPRING

An ordinary spring is a
natural flowing of
groundwater out onto
the surface
ARTESIAN WELL

A manmade hole where
water flows freely
without being pumped
ARTESIAN SPRING
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Water flowing through
cracks in impermeable
rock